On a manufacturing line for semiconductor substrates, thin-film substrates, and so on, defects present on or in the surfaces of the semiconductor substrates, thin-film substrates, and so on are inspected to maintain or improve the product yield.
As a conventional technique, an inspection device or tool for inspecting defects having dimensions from tens of nm to the order of microns or more by directing a laser beam collected to tens of microns at the surface of a sample for detecting microscopic defects and collecting and detecting scattering light from the defects is disclosed in patent literature 1 (JP-A-9-304289). An inspection tool for classifying defects by detecting those components of scattering light from the defects which exit at high angles and those components which exit at low angles and relying on their ratio is disclosed in patent literature 2 (JP-A-2006-201179).
Furthermore, patent literature 3 (JP-A-2008-32600) discloses an “outer appearance inspection tool having a signal combining portion for combining detection signals based on scattering light generated from a surface of a sample according to set conditions, a condition setting portion for setting conditions under which the detection signals are combined together by the signal combining portion, and a display portion for displaying a synthesized sample image built based on the resulting signal created by the signal combining portion according to the conditions set by the condition setting portion”.